I agree Quests as research makes no sense for me too...

If there needs to be some guards, I would put this more in the spells area:

- Unlock dungeon (the dungeon was closed to protect the outside from the evil within by a powerful mage).

This would offer even more granularity...Some quests are available from the start and for others you need more and more powerful spells...

But to my understanding adventuring research is the way to the research victory by fulfiling the ultimate quest, or am I wrong?

I think the proper type of flavor text and descriptors would make this seem a lot less artificial. Unlocking "techs" on the Adventuring path could be presented as various tales of knowledge and valor, such as the scholar that successfully translated an ancient scroll or the one about the hapless band that discovered which end of the dragon shoots the fire.

As it is it makes limited sense. I think resarching questing as an absolute neccesity in order to be able to quest is not too solid. A sovereign or hero can very well walk into a cave, right? Who cares what they were taught at school, they should be able to march into a cave or to talk to individuals regardless of your state  of research.

However, I feel hat researching quests has some merit. Maybe you can initiate any quest at any time, but in order to fully understand how dangerous a quest is you need to know a little bit more. Compare it to this: Any one can walk straight into the desert, but knowing how to survive there when water runs out requires skill and knowledge. You should know what to be aware of, how to increase your chances of finding water, what you can and cannot eat, where the critters who are edible are hiding, etc. Likewise, I feel that in Elemental anyone should be able to undertake quests, regardless of training or research. However, I think that research should help in learning how dangerous quests are. For example:

• A certain smell near the entrance of a cave may not even be noticed by a rookie undertaking his frst quest;
• A beginner who did a quest or two may know he should pay attention to things like the smell so he notices the smell and knows to be on his guard;
• A veteran may recognise the smell as a sign of a certain group of creatures and know what to be on the lookout for and what to do and what not to do;
• And a master may recognise the smell as a sign of a certain group of creatures, knows to look for feces to specify which particular kind of creature may be present here, finds the feces and determines it is the kind that climbs really well and knows to keep looking up in order to be really safe. Also the master knows that is he encounters bones of mice, the predator may very well be very, very close and therefore the master may even attempt to scare the predatory creature away even though it is not spotted yet.